Abstract The aim was to evaluate the effect of the inclusion of wheat bulgur in the diet on intake, digestibility, N balance and ruminal parameters in cannulated lambs. Four castrated Santa Ines×Dorper lambs, cannulated in the rumen, (45 ± 9 kg) were housed in metabolism crates. They were randomly distributed in a 4×4 Latin Square,10-day adaption, a 6-day sampling period. The base diet was composed by ryegrass hay and concentrate, in a 40:60 roughage:concentrate ratio and four inclusions of wheat bulgur on the total diet: 0, 190, 380 and 570 g/kg dry matter. The inclusion of wheat bulgur did not affect the intake of non-structural carbohydrates. The intake of dry matter, fiber, crude protein, organic matter and crude fat decreased linearly (P<0.05). The digestibility of neutral detergent fiber decreased linearly (P=0.001). The N retained and the excreted in urine were not affected by wheat bulgur inclusion. Fecal excretion, total excretion and absorbed N, decreased linearly (P<0.05). There was no change on pH, ammonia, soluble carbohydrates and protozoa population in rumen. Increasing of wheat bulgur in the diet of lambs decrease the nutrient intake and fiber digestibility without affecting the digestibility of other compounds, ruminal parameters, and the protozoa count.

Abstract The objective of this work was to compare the zootechnical performance of Dorper x Santa Inês crossbred lambs finished in grazing systems on Megathyrsus maximus Aruana cultivar pasture, with and without shading, and in a feedlot. Twenty-four non-castrated lambs were used in a completely randomized experimental design, with the three following treatments with eight replicates each: 'Aruana' pasture without shading + supplement; 'Aruana' pasture with shading + supplement; and feedlot, with diet containing ryegrass hay and concentrate at a 20:80 ratio. The treatments did not influence lamb age at slaughter, birth weight, leg compactness, true yield, and main cut yield, except that of breast tip + flank that was lower for the pasture with shading. However, average daily gain, body condition score, live weight at slaughter, carcass compactness index, cold carcass and empty body weights, and cold carcass yield differed between treatments, showing higher values in the feedlot. Termination in the feedlot increases the zootechnical performance of Dorper x Santa Inês sheep and favors a lower age at slaughter, as well as a greater weight of the main commercial cuts, but not their yield.

Resumo O objetivo deste trabalho foi comparar o desempenho zootécnico de cordeiros mestiços Dorper x Santa Inês terminados em sistemas de pastejo sobre pastagem de Megathyrsus maximus cultivar Aruana, com e sem sombreamento, e em confinamento. Utilizaram-se 24 cordeiros não castrados em delineamento experimental inteiramente casualizado, com os três seguintes tratamentos, com oito repetições cada um: pastagem de 'Aruana' sem sombreamento + suplemento; pastagem de 'Aruana' com sombreamento + suplemento; e confinamento, com dieta contendo feno de azevém e concentrado na proporção de 20:80. Os tratamentos não influenciaram a idade dos cordeiros até ao abate, o peso ao nascer, a compacidade da perna, o rendimento verdadeiro e o rendimento dos cortes principais, exceto o da ponta do peito + flanco que foi menor na pastagem com sombreamento. Entretanto, o ganho médio diário, o escore de condição corporal, o peso vivo ao abate, o índice de compacidade da carcaça, os pesos da carcaça fria e do corpo vazio, e o rendimento de carcaça fria diferiram entre os tratamentos, com valores superiores no confinamento. A terminação em confinamento aumenta o desempenho zootécnico de ovinos Dorper x Santa Inês e favorece a menor idade ao abate, bem como o maior peso dos principais cortes comerciais, mas não o seu rendimento.

Abstract The objective of this work was to evaluate the effect of the addition of whole-crude oilseeds of linseed, sunflower, and soybean to the diet of Jersey cows, in the first third of lactation, on the following characteristics: intake, apparent nutrient digestibility, milk production and its variables, energy-corrected milk, feed efficiency, energy balance, milk fatty acid profile, and blood metabolic profile. Eight multiparous Jersey cows were used in a double Latin square design. The treatments were the experimental diets with the oilseeds, and calcium salts of fatty acids were used as the control. Protein digestibility was lower for soybean, whereas that of ether extract was higher in the control, not differing between the evaluated oilseeds. There was no difference between oilseeds for milk production, milk production corrected for fat, milk nutritional content, feed efficiency, energy balance, and blood metabolic profile. The levels of mil k monou n sat u rated fatty acids increased with the use of sunflower. Higher levels of cis-9, trans-11 conjugated linoleic acid (CLA) in milk were observed in the control. The addition of the evaluated whole-crude oilseeds to the diet of Jersey cows in the first third of lactation does not affect milk production variables, feed efficiency, energy balance, and blood biochemical profile, but alters the fatty acid profile.

Resumo O objetivo deste trabalho foi avaliar o efeito da adição de grãos integrais das oleaginosas linhaça, girassol e soja na dieta de vacas Jersey, no primeiro terço da lactação, sobre as seguintes características: consumo, digestibilidade aparente dos nutrientes, produção de leite e suas variáveis, leite com correção energética, eficiência alimentar, balanço energético, perfil de ácidos graxos do leite e perfil metabólico sanguíneo. Oito vacas Jersey multíparas foram utilizadas em delineamento duplo quadrado latino. Os tratamentos foram as dietas experimentais com as oleaginosas, e sais de cálcio de ácidos graxos foram utilizados como o controle. A digestibilidade da proteína foi menor para a soja, enquanto a do extrato etéreo foi maior no controle, sem diferir entre as oleaginosas. Não houve diferença entre as oleaginosas para produção de leite, produção de leite corrigida para gordura, conteúdo nutricional do leite, eficiência alimentar, balanço energético e perfil metabólico sanguíneo. Os teores de ácidos graxos monoinsaturados no leite aumentaram com uso do girassol. Níveis mais altos de ácido linoleico conjugado cis-9 trans-11 no leite foram observados no controle. A adição das oleaginosas integrais avaliadas na dieta de vacas Jersey, no primeiro terço da lactação, não afeta as variáveis de produção de leite, a eficiência alimentar, o balanço energético e o perfil metabólico sanguíneo, mas altera o perfil de ácidos graxos.

ABSTRACT Our objective was to identify the best fit mathematical models for in vitro gas production kinetics using rumen fluid and forage plants commonly used in ruminant feed to obtain better estimates of parameters that describe the rumen fermentation. Four mathematical models were tested, two unicompartmental (M1 = first order, M2 = Gompertz) and two bicompartmental (M3 = M1 + M2; M4 = M2 + M2). Two temperate grasses were evaluated, as well as four tropical grasses and three temperate forage legumes. The fit of the models was verified by the corrected Akaike information criterion (AICcr) and the difference among AICcr values (Δr), likelihood probability (Wr), and relative likelihood (ERr). Temperate forages reached maximum gas production between 48 and 72 h. In the tropical forages, it occurred only after 72 h. In profiles in which M3 was the best choice, the values of parameters Vf 1 were higher than those of Vf 2, and k1 values were higher than k2 values. The only exception was for Tifton 85 profile, whose Vf 2 value was higher than Vf 1. The model M3 has a better fit for tropical forages with higher fiber content and lower levels of nonfibrous carbohydrates and crude protein. The model M1 has a better fit for forage with higher nonfibrous carbohydrate contents and low lignin content.

ABSTRACT. Sugar cane is highly productive (dry matter.hectare-1), but after ensiling process nutritional quality is affected, thus additives are needed to control or minimize losses. This study aimed to evaluate if Lactobacillus plantarum LPBR01 strain used as silage inoculant for sugar cane can control fermentation losses. Sugar cane samples (72) were divided in two treatments with three replicates, control (no Lactobacillus) and treatment silage with Lactobacillus (106 CFU g-1 of silage). Nutritional composition of samples in different periods of fermentation (0, 7, 15, 30 and 45 days) was estimated by determining levels of dry matter (DM), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), hemicellulose (HEM), mineral matter (MM) and acid detergent lignin (ADL). Fermentative profile of the silage was characterized by determining sugars, ammoniacal nitrogen, acidity and pH at 0, 12, 24, 36, 48, 60 and 72 hours. Inoculation of sugar cane silage with Lactobacillus plantarum LPBR01 strain presented no significant results (p ≤ 0, 5) however, interaction between treatment and day (p ≤ 0, 5) could be observed for the levels of ADF. The Lactobacillus plantarum LPBR01 strain was not efficient to control the fermentation losses that occur in the silages of sugar cane at the concentration used in this study.

RESUMO O objetivo com este estudo foi determinar a qualidade nutricional da aveia (Avena sativa L.) IPR 126, a fim de produzir forragem para ruminantes. Foram utilizados quatro períodos entre os cortes: 14, 21, 28 e 35 dias, distribuídos em blocos casualizados com quatro repetições para cada tratamento. As variáveis avaliadas foram: a concentração de fibra insolúvel em detergente neutro (FDN), lignina, matéria seca (MS), cinzas, extrato etéreo (EE) e digestibilidade in vitro da matéria seca obtida pela medição da produção de gás. O perfil de produção de gás foi ajustado ao modelo logístico bicompartimental. As variáveis e os parâmetros ajustados às curvas de produção de gás foram analisados como medidas repetidas através do PROC MIXED do SAS (versão 9.0) e a máxima verossimilhança restrita (REML) como o método de estimação de parâmetros. A análise de regressão foi realizada para as variáveis: MS, PB, EE, FDN, cinzas, e para o parâmetro k2 do modelo bicompartimental. As concentrações de MS e FDN aumentaram linearmente, PB, cinza, e as estimativas do parâmetro k2 diminuíram de forma linear e a concentração de EE apresentou comportamento cúbico em função da idade de colheita. A lignina e outros parâmetros do modelo de Schofield não foram influenciados pela idade de colheita. O intervalo de colheita influenciou alguns componentes químicos e taxa de degradação de carboidratos de fibra, mas não na concentração de lignina. A forragem com 21 dias de intervalo de corte apresentou maior valor nutricional.

SUMMARY The present study aiming to determine the nutritional quality of oat (Avena sativa L.) IPR 126 in order to produce forage for ruminants. Four periods between harvests were used: 14, 21, 28 and 35 days, distributed in randomized blocks with four replicates for each treatment. The variables evaluated were: the concentration of dry matter (DM), neutral detergent insoluble fiber (NDF), crude potein (CP), lignin, dry matter (DM), ash, ether extract (EE) and in vitro digestibility of dry matter obtained by measurement of gas production. The profile of gas production was adjusted to the logistic bicompartimental mathematical model. The variables and the parameters of the adjusted gas production curves were analyzed as repeated measurements through the PROC MIXED of SAS (version 9.0) and the restricted maximum likelihood (REML) as the method of estimation of parameters. Regression analysis was performed for the variables: DM, CP, EE, NDF, ash, and for the parameter k2 of the bicompartimental model. DM and NDF concentrations increased linearly, CP, ash, and the estimations of the parameter k2 reduced linearly and the EE concentration showed a cubic behavior in function of the age of harvest. Lignin and other parameters of the Schofield model were not influenced by the age of harvest. The harvest interval influenced some chemical components and degradation rate of fiber carbohydrates, but do not interfere in lignin concentration. The forage with 21 days of cutting interval has the high nutritional value.

RESUMO Objetivou-se com este estudo realizar uma comparação do poder de predição de diferentes equações do consumo de matéria seca de vacas leiteiras. O trabalho foi conduzido por meio de pesquisas na literatura coletando informações sobre massa corporal, produção de leite, dias de lactação, consumo de matéria seca e teor de gordura no leite de vacas leiteiras criadas no Brasil. Todas essas informações, menos o consumo de matéria seca observado, foram utilizadas para calcular o consumo de matéria seca predito com as equações dos modelos: National Research Council (NRC, 2001), Cornell Net Carbohydrate and Protein System (CNCPS, 2004), Agricultural and Food Research Council (AFRC, 1993) e De Freitas et al. (2006). Posteriormente, as estimativas das equações foram usadas para avaliar o poder de predição dos modelos por meio da comparação gráfica dos seus resíduos padronizados conforme Draper & Smith (1966) e Montgomery (2005) e do critério de Akaike (AKAIKE, 1974). Para os dados analisados neste estudo, o NRC (2001) foi considerado como melhor escolha por apresentar o ERr = 1. Os demais, apresentaram ERr maior do que 20 e, portanto, não foram adequados para a predição do CMS. O modelo AFRC (1993) apresentou tendência a subestimar os valores preditos com 76% dos pontos acima da linha de nulidade.

SUMMARY The present study aimed to perform a comparison of the predictive power of different equations to estimate intake by dairy cows. The work was conducted through collecting information in literature about body weight, milk yield, days in milk, dry matter intake and fat content of milk of dairy cows raised in Brazil. All this information, with the exception of dry matter intake, were used to predict the dry matter intake with equations of the model: National Research Council (NRC, 2001), Cornell Net Protein and Carbohydrate System (CNCPS, 2004), Agricultural and Food Research Council (AFRC, 1993) and De Freitas et al. (2006). Subsequently, the predictive power of the mathematical equations was compared through the graphical comparison of the standard as Draper and Smith (1966) and Montgomery (2005) and by means of Akaike's criterion (Akaike, 1974) waste. NRC (2001) was the best choice for presenting the ERr = 1, all others showed ERr much greater than 20 and therefore must be considered worse choices. AFRC (1993) has tended to underestimate the predicted values with 76% points above the line of invalidity. Model NRC (2001) is the one that best predicts the dry matter intake of dairy cows under the conditions studied.

A inclusão de leguminosas na dieta tem o potencial de melhorar a produtividade e sustentabilidade dos sistemas de produção de ruminantes em regiões tropicais. Contudo, não está bem estabelecido quais componentes químicos são os mais determinantes do seu valor nutricional. Este estudo avaliou a relação entre componentes químicos e a digestão in vitro de leguminosas forrageiras tropicais, com o objetivo de obter indicadores de seu potencial nutricional. Foram incluídas amostras de Crotalaria spectabilis, Cajanus cajan, Macrotyloma axillare, Mucuna aterrina, Stylosantis sp. e Canavalia ensiformis cortadas de plantas com idades de crescimento entre 47 a 110 dias. O volume de gases apresentou correlação negativa (P<0,05) com os teores de N (R=-0,51), fibra em detergente ácido (FDA, R=-0.62) e lignina em detergente ácido (LDA, R=-0,65), e positiva com o teor de carboidratos não fibrosos (CNF, R=0,70) das leguminosas. A taxa de produção de gases foi negativamente relacionada (P<0.05) com os teores de FDN (R=-0.73), FDA (R=-0.62) e LDA (R=-0.74). A concentração de amônia no meio foi positivamente correlacionada (P<0.05) com o teor de N total (R=0.74) e N solúvel (R=0.56) e, negativamente, correlacionada com o teor de CNF (R=-0.81). O grau de aderência bacteriana no resíduo de incubação foi negativamente relacionada (P<0.05) com os componentes da parede celular, principalmente com o teor de LDA (R=-0.57). A adição de polietileno glicol aumentou o volume e a taxa de produção de gases das leguminosas, e reduziu a concentração de amônia no meio de incubação (P<0,05). Em conclusão, mesmo em baixas concentrações, os taninos impactam a fermentação ruminal de leguminosas forrageiras tropicais. Contudo, o teor de LDA representa o melhor indicador do potencial nutricional dessas forrageiras.

Inclusion of forage legumes in diet may improve tropical ruminant systems productivity and sustainability. However, it is not well stablished which chemical components more impact their nutritional value. The relationship between chemical composition and in vitro fermentation of tropical forage legume was evaluated with the objective of obtaining indicators of their nutritional value. Samples of Crotalaria spectabilis, Cajanus cajan, Macrotyloma axillare, Mucuna aterrina, Stylosantis sp. and Canavalia ensiformis, cut from plants at growth age between 47 to 110 days, were analysed. Total gas production showed negative correlation (P<0.05) with total N (R=-0.51), acid detergent fibre (ADF, R=-0.62) and acid detergent lignin (ADL, R=-0.65), and positive correlation with non-fibre carbohydrates (NFC, R=0.70). Gas production rate was negatively related (P<0.05) to NDF (R=-0.73), ADF (R=-0.62) and ADL (R=-0.74). Ammonia concentration in the incubation medium was positively related (P<0.05) to total (R=0.74) and soluble (R=0.56) N, and negatively related to NFC (R=-0.81). The level of bacterial adhesion on residue of incubation was negatively related (P<0.05) to cell wall components, mainly to ADL (R=-0.57). The inclusion of polyehtylene glycol increased both gas volume and gas production rate whereas decreased ammonia concentration (P<0.05). In conclusion, even at low concentrations tannins impact the in vitro fermentation of tropical legumes. However, among the analyzed chemical components, the ADL was the best indicator of the nutritional value of the tropical forage legumes.